The present invention relates to a device for blocking the entrance of a sheet feeder, and more particularly to a device to prevent the introduction of further sheets into the entry hopper of a feeder when at least one sheet is still present in the hopper.
A device of this type may be used in copying machines, printers and other similar office machines having automatic sheet feeders.
It is known, in conventional sheet feeders, that after the pick-up roller has advanced a sheet, the next sheet remains gripped between a roller and a double sheet rejection block. As a result of this, if other sheets are introduced, they will become trapped between the pick-up roller and the current sheet. Consequently, on the next actuation of the pick-up roller the added sheets will be advanced in a group, causing a jam in the feeder.